1. Field of the Invention
The present invention relates to a rotary hook assembly for a sewing machine.
2. Description of the Prior Art
In a conventional rotary hook assembly, a rotary hook rotates such that a guide groove formed in the rotary hook receives a guide rim formed in a bobbin case basket. Accordingly when the sewing machine is operated at a high speed, seizure may be caused by friction generated between the contacting faces of the rotary hook and the bobbin case basket. Furthermore, since the bobbin case basket may be forced to rotate in a direction equal to the direction of the rotary hook by the seizure thus generated, there may be generated resistance on a bobbin case basket retaining member, which would render it difficult for a needle thread to pass between the bobbin case basket and the retaining member, or cause the thread to break during the formation of seams.